maya cities tended to expand haphazardly, and the city centre would be occupied by ceremonial and administrative complexes, surrounded by an irregular sprawl of residential districts. different parts of a city would often be linked by causeways. the principal architecture of the city consisted of palaces, pyramidtemples, ceremonial ballcourts, and structures aligned for astronomical observation. the maya elite were literate, and developed a complex system of hieroglyphic writing that was the most advanced in the precolumbian americas. the maya recorded their history and ritual knowledge in screenfold books, of which only three uncontested examples remain, the rest having been destroyed by the spanish. there are also a great many examples of maya text found on stelae and ceramics. the maya developed a highly complex series of interlocking ritual calendars, and employed mathematics that included one of the earliest instances of the explicit zero in the world. as a part of their religion, the maya practised human sacrifice